diff options
| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2011-04-20 15:57:14 +0200 |
|---|---|---|
| committer | Andi Kleen <ak@linux.intel.com> | 2011-04-28 08:21:15 -0700 |
| commit | f0aa357c5f66cc5befc35d5d438d323182cdeb2a (patch) | |
| tree | 73312adea575ed3e93aae94d61e512c1beae9f6e | |
| parent | 98081a1026dd80b985a084df2678e7d032729f6d (diff) | |
iwlwifi: fix skb usage after free
[AK: Did some changes for the backport to .35. Stanislaw, please verify
them]
Since
commit a120e912eb51e347f36c71b60a1d13af74d30e83
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Fri Feb 19 15:47:33 2010 -0800
iwlwifi: sanity check before counting number of tfds can be free
we use skb->data after calling ieee80211_tx_status_irqsafe(), which
could free skb instantly.
On current kernels I do not observe practical problems related with
bug, but on 2.6.35.y it cause random system hangs when stressing
wireless link.
Cc: stable@kernel.org # 2.6.32+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl-agn-tx.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c index 3a3d27c20c42..cf64575067e5 100644 --- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c +++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c @@ -1141,11 +1141,14 @@ int iwlagn_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index) q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) { tx_info = &txq->txb[txq->q.read_ptr]; - iwlagn_tx_status(priv, tx_info->skb[0]); + + if (WARN_ON_ONCE(tx_info->skb[0] == NULL)) + continue; hdr = (struct ieee80211_hdr *)tx_info->skb[0]->data; - if (hdr && ieee80211_is_data_qos(hdr->frame_control)) + if (ieee80211_is_data_qos(hdr->frame_control)) nfreed++; + iwlagn_tx_status(priv, tx_info->skb[0]); tx_info->skb[0] = NULL; if (priv->cfg->ops->lib->txq_inval_byte_cnt_tbl) |